FIG. 1 shows a conventional dual HVAC system 100, which requires two independent HVAC units, a front HVAC unit 102 to cool the front of the vehicle and a rear HVAC unit 104 to cool the rear of the vehicle. The front HVAC unit 102 and the rear HVAC unit 104 are each housed in separate housings whereby the front HVAC unit 102 is disposed toward the front of the vehicle and the rear HVAC unit 104 is disposed toward the rear of the vehicle.
The front HVAC unit 102 includes a front blower (not shown), an evaporator 106F, a heating core 108F, and an air mix door 110. The air mix door 110 is movable between a first position whereby all the air is directed through the heating core 108F and a second position where all the air is directed through the evaporator 106F. Airflow through the evaporator 106F, the heating core 108F or a combination thereof is directed to one or more of a defroster outlet 112, a vent outlet 114, or a heater outlet 116.
The front HVAC unit 102 further includes a defroster door 118 and a vent/heater door 120. The defroster door 118 is movable between a first and second position to regulate the amount of airflow that exits the defroster outlet 112. When the defroster door 118 is in the first position the defroster outlet 112 is closed and airflow is directed to the vent outlet 114, the heater outlet 116 or a combination thereof. When the defroster door is in the second position the defroster outlet 112 is open and the airflow exits through the defroster outlet 112. The vent/heater door 120 is also movable between a first and second position to regulate airflow through the vent outlet 114 and the heater outlet 116 in a similar manner as the defroster door 118.
The rear HVAC unit 104 also includes an evaporator 106R and a heating core 108R. The rear HVAC unit 104 further includes a rear blower 122, an air mix door 124, and an airflow direction door 126. The air mix door 124 operates in a similar manner to the air mix door 110 in the front HVAC unit 102. The airflow direction door 126 regulates airflow between one or more upper vents 128 and one or more floor vents 130.
Thus, a major disadvantage to the conventional dual HVAC system 100 is the requirement of two housings, two evaporators 106F, 106R, and two heating cores 108F, 108R, which increases assembly and manufacturing costs.
Another disadvantage to the conventional dual HVAC system 100 is that because the rear HVAC unit 104 is located toward the rear of the vehicle, the rear HVAC unit 104 requires a longer refrigerant line 132 and heating core line 134, which in turn leads to increased material and assembly costs. Further, more connecting joints are required to run the refrigerant line 132 and the heating core line 134 from the engine compartment to the rear HVAC unit 104, thereby increasing the probability of fluid leaking at any one joint in each line.
Yet another disadvantage to the conventional HVAC system 100 is that the rear HVAC unit 104 occupies space in a center console 136 that can otherwise be utilized as storage space. Specifically, the rear HVAC unit 104 is located in the center console 136 below an arm rest 138 and a storage compartment 140. As clearly show in FIG. 1, the rear HVAC unit 104 limits the amount of storage space in the center console 136.
Thus, what is required is a dual HVAC system that overcomes the above mentioned disadvantages.